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Archive for the ‘Fire’ Category

Canberra could be hit by catastrophic bushfires on the same scale as the 2003 inferno every eight years by 2050, according to a new study on the impacts of climate change, reported The Canberra Times (27/9/2007, p.3).

The great Aussie backyard burn-off has been banned under a State Government plan to clean up air quality in metropolitan NSW, reported The Daily Telegraph (5/9/2007, p.7). Read the rest of this entry »

In a study released by the British journal Nature, the investigators said the so-called Asian Brown Cloud was as much to blame as greenhouse gases for the warming observed in the Himalayas over the past half century, reported The Canberra Times (2/8/2007, p.3).

Glaciers melt now, but droughts loom later: Rapid melting among the 46,000 glaciers on the Tibetan Plateau, the third-largest ice mass on the planet, was already causing downstream flooding. But long-term worries focus more on the danger of drought, as the glaciers shrink. The report triggered an appeal from UN Environment Program chief Achim Steiner, who urged the international community “to ever greater action” on tackling climate change.

UAVs monitor Cloud from above: Researchers led by Veerabhadran Ramanathan, a professor of atmospheric sciences at Scripps Institution of Oceanography in California, used an innovative technique to explore the Asian Brown Cloud. The plume sprawls across South Asia, parts of Southeast Asia and the northern Indian Ocean. It spews from tailpipes, factory chimneys and power plants, forests or fields that were being burned for agriculture, and wood and dung which are burned for fuel. Professor Ramanathan’s team used three unmanned aircraft fitted with 15 instruments to monitor temperature, clouds, humidity and aerosols. The remote-controlled craft carried out 18 missions in March 2006, flying in a vertical stack over the Indian Ocean. The planes flew simultaneously through the Brown Cloud at heights of 500m, 1500m and 3000m.

Cloud exacerbates solar heating, melts mountain ice: They discovered that the cloud boosted the effect of solar heating on the air around it by nearly 50 per cent because its particles are soot, which is black and thus absorbs sunlight. The simulation estimated that, since 1950, South Asia’s atmosphere has warmed by 0.25C per decade at altitudes ranging from 2000m to 5000m above sea level – the height where thousands of Himalayan glaciers are located. As much as half of this warming could be attributed to the effects of brown clouds, Professor Ramanathan said.

Biomass burning produces Cloud: Roughly 60 per cent of the soot in South Asia comes from biofuel cooking and biomass burning, which could be eased by helping the rural poor get bottled gas or solar cookers, he said.